Vessel and lumen expander attachment for use with an electromechanical driver device

ABSTRACT

A selectively coupleable and remotely actuateable surgical attachment for use with an electromechanical driver device for use in expanding occluded vessels and lumens. The attachment includes an axial rod which is coupleable to the electromechanical driver device, and which is selectively rotateable in accordance with the action of the electromechanical driver device. The rod is also threaded in opposing orientations at either end thereof. A pair of nuts are mounted to the rod, and specifically on the opposing threads. The rod and nuts are disposed within an axial track which permits the rod to turn, but constrains the rotational motion of the nuts, thereby permitting the nuts to move axially along the threadings of the rod when the rod turns. Attached to the nuts are a series of jointed spokes which are coupled to a flexible tubular shroud which surrounds the entire assembly. The jointed spokes are radially extended and retracted in accordance with the motion of the nuts in an umbrella-like fashion in accordance with the actuation of the electromechanical driver device. The radial expansion of the flexible tubular shroud provides the necessary force to expand an occluded vessel or lumen.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to an attachment for use with anelectromechanical driver device, and more specifically to a vascularexpander device which is insertable, expandable, collapsible, andremovable within and from a vascular, lumen, or similar vessel by meansof a remote electromechanical driver device.

2. Description of the Prior Art

Upon identification of a stricture and/or stenosis in an artery,gastrointestinal tract, bowel, or other vessel of the body (for anotherimportant example, the bile duct) several treatment actions may beselected. Surgical intervention may include fully invasive proceduressuch as bypasses in which supplemental vessels are transplanted fromother regions of the body, or in less frequent circumstances, artificialsupplemental structures are implanted. This fully invasive procedureoften requires significant hospitalization and tremendousrehabilitation. For these reasons, it has been a goal of the industry tominimize the number of instances in which these procedures are performedto the barest minimum. The less invasive surgical intervention, whichhas become more desirable, is one in which a device is inserted into thesegment of the vessel which has narrowed, and to inflate the devicewithin the segment until the passage through the vessel has beenexpanded to a more acceptable diameter. This procedure has been widelyaccepted and is only untenable in situations where the stenosis hasoccurred to such a great extent that the device cannot be inserted.Target tissues for such procedures, as mentioned above, includecardiovascular arteries which have sclerosed, peripheral vasculararteries which have sclerosed, bowel tissue which has narrowed due toscarring or other narrowing event, to an extent that such sclerosing ornarrowing inhibits the proper flow of digestion, and normal use of anyother soft tissue vessel which has sufficient elasticity to expand.

While the methodological innovation of expanding a structure within astenosed vessel to increase flow therethrough to a more desirable levelis one of the great advances in medicine of the last few decades, theinstruments utilized in the execution of these procedures have laggedsubstantially behind the development curve. The traditional instrumentfor such a procedure, for example, a dilation balloon catheter for anangioplasty, is a long flexible tube having a selectively expandablevolume disposed in the tip of the device. This tube having theexpandable volume in its tip is directed through the femoral artery, theaorta, and into the heart itself. From the heart, it is directed intothe partially blocked vessel. Once the tip of the device is disposed inthe narrowed channel, a fluid (usually saline) is advanced into theflexible expanding volume to cause it to inflate. The inflating balloonpresses against the walls of the vessel, causing them to expandoutwardly. This process is continued until the vessel is enlarged to thepoint that the physician feels that the flow through it will besufficient to alleviate the symptoms and potential for damage.

One of the most important drawbacks of the balloon catheter design isthat the means for inflating the volume, and the manner in which thevolume is inflated, completely blocks the flow of fluids through thevessel during the procedure. This failure is inherent in the design byvirtue of the fact that the balloon must occlude the vessel in order toapply the pressure to the walls. A few alternative designs have beenproposed in the art which provide a minimal solution to the problem byoffering a number of cannulae, or narrow and rigid pass through holes,formed in the balloon itself, for permitting a small amount of fluid toflow when the balloon is fully inflated.

This attempted solution further highlights (and exacerbates) the otherimportant failure of balloon type devices. This failure relates to thegathering of information about the expansion of the vessel walls. Moreparticularly, one of the important measurements involved with any vesselexpansion is the change in diameter, which is attained at a giveninternal pressure of the balloon. The relationship of pressure anddiameter is inherently imprecise as vessel tissue varies in elasticityacross the spectrum of potential patients as well as the degree ofexpansion or vessel narrowing which has already taken place (forexample, a second or third angioplasty might proceed with a completelydifferent pressure to diameter profile from that of a first timeprocedure). The inclusion of narrow passages through the expandingvolume, especially in the case of a balloon having a cannulatedstructure, results in a very unreliable interior pressure to diameterrelationship.

Unfortunately, it is also not always the case that the one timeexpansion of the vessel (during the surgical intervention) continues toremain effective over a long period. The stenosis of the vessel oftencontinues, and the flow through the treated area may drop again to alevel requiring additional intervention. As repeated expansion of thevessel stresses the tissue, and has been linked to the formation ofaneurysms, it has been found necessary to install a permanent structuralelement into the vessel. These structural elements, which are generallyreferred to as stents, are generally tubular in shape, but are formed ina variety of different manners, including solid cylinders, meshes,fabrics, etc. The introduction of a stent into a patient usually followsa traditional angioplasty procedure, during which the vessel is expandedto the necessary diameter for the stent to be inserted. The remoteinstallation of a stent is difficult, but several designs have beenoffered in which the stent is delivered in a collapsed form, and is thenirreversibly expanded into position by means incorporated into theinsertion tube. The diameter of a specific stent is, therefore,predetermined, and the diameter of the stent selected must be pickedcorrectly.

It has been found, however, that over time, the stent is incorporated bythe body, into the tissue wall of the vessel. Continued stenosis of thevessel around, and/or through the stent, presents an immediatelyunderstandable problem for continued treatment, i.e., the stent is arigid metal structure which will prevent an angioplasty procedure frombeing able to expand the vessel (the balloon will expand against thestent, and the stent will remain undeflected).

Removal of a stent which has already been incorporated by the body is aconsiderable problem. Techniques of sheering off the tissue which hasbuilt up on and around the inside of the stent have been provided in theart, however, these generally include a rotating blade within thevessel. The risks of particulate matter becoming dislodged within thevessel, and causing considerable damage as a result, as well as thepotential for weakening the structural integrity of the vessel walls tothe point of rupture has limited the applicability of this technique. Inthe final analysis, stents have a tainted usefulness insofar as they mayalleviate the stenosed condition for a short period, but may preordainand require a full bypass procedure if the vessel begins to re-stenose(which occurs in a vast number of such cases).

It is also a failure of the present instrumentation that as with manysuch devices of the prior art, all of these devices are considered fullydisposable, and are, in fact, thrown away after a single use. They arecomplicated devices, having multiple moving parts, requiring substantialstructural integrity and, therefore, expense in manufacturing. The factthat they are used only once, and no part can be used again render theuse of such devices expensive and wasteful of resources.

In addition to this failure, as can be readily observed from thepreceding descriptions, the prior art devices suffer from numerous otherlimitations, which would be desirable to overcome. These includes therequirement that the surgeon manually actuate all of the features andfunctions of the balloon catheter and the fact that the angioplastyballoon inflates to a discrete size, necessitating the replacement of anundersized balloon with the next size balloon. This process may berepeated numerous times until the appropriate diameter is achieved. Anyand all undersized balloons are wasted during this procedure.

It is, therefore, a principal object of the present invention to providea device which may be remotely actuated to expand and apply a radiallyoutward pressure against the walls of a narrowed vessel or lumen inconjunction with and in accordance with a surgical procedure.

It is further an object of the present invention to provide aninstrument for expanding tissue during gastrointestinal surgery,cardiovascular angioplasty, peripheral vascular angioplasty, and otherprocedures, which will reduce the waste of resources and facilitate arange of expansion (for example, eliminating the need for sizing thevessels as described above) by permitting use as an attachment to anelectromechanical driver device.

It is further an object of the present invention to provide a devicewhich reduces the requirements for the surgeon, gastroenterologist, orcardiologist to manually actuate different components and mechanisms.

It is further an object of the present invention to provide a devicewhich does not occlude the vessel in which it is expanding, therebypermitting a significant flow of fluid to continue as it expands againstthe vessel or lumen walls.

It is further an object of the present invention that at least a portionof the expanding section of the device be selectively disengageable andimplantable within the vessel or lumen if it is determined that thevessel or lumen requires a permanent structural support.

It is further an object of the present invention that the device, and inparticular the portion which may be selectively permanently implanted inthe vessel or lumen, be expandable through and permanently (and rigidly)expanded to a diameter within a range of different diameters.

Other objects of the present invention shall be recognized in accordancewith the description thereof provided hereinbelow in the Summary of theInvention, and in the Detailed Description of Preferred Embodiments inconjunction with the Figures.

SUMMARY OF THE INVENTION

The preceding objects of the invention are provided by an attachment ofthe present invention which is coupled with, and actuated by, anelectromechanical driver device set forth in more complete detail inU.S. Ser. No. 09/324,452, entitled “An Electromechanical Driver Devicefor use with Anastomosing, Stapling, and Resecting Instruments”,assigned to the same assignee of the present invention. Moreparticularly, the attachment may be embodied in a variety of differentstructures, a preferred one being set forth in more detail hereinbelow.Each embodiment of the attachment, however, is coupleable to the distalend of the flexible shaft of the electromechanical driver device whichcauses the attachment, among other additional functions, to expand andcontract upon proper remote actuation of the electromechanical driverdevice and in accordance therewith.

More specifically, the electromechanical driver device comp rises ahandle and a flexible drive shaft. The handle has a pistol grip-styleddesign, having a finger trigger which is independently coupled to amotor which turns a flexible drive shaft (described more fullyhereinbelow). The motor is a dual direction motor, and is coupled to amanual drive switch mounted to the top of the handle, by which thesurgeon user can selectively alter the turning direction of the motor.This dual direction capacity may be most simply achieved by selecting amotor which turns in a direction corresponding to the direction ofcurrent, and actuation of the manual drive switch alters the directionof the current accordingly. In this example, the power source supplyingthe motor must be a direct current source, such as a battery pack (andmost desirably, a rechargeable battery pack). In the event that thedevice should be useable with an alternating current, either atransformer can be included, or a more sophisticated intermediategearing assembly may be provided. In conjunction with the presentdescription, the embodiments of the present invention which will bedescribed utilize a rechargeable battery pack providing a directcurrent.

In addition to the motor components, the handle may further includeseveral other features, including: (1) a remote status indicator; (2) ashaft steering means; and (3) at least one additional electrical supply.First, the remote status indicator may comprise an LCD (or similar readout device) by which the user may gain knowledge of the position ofcomponents (for example whether the spokes are at the closed position orat a definite expanded diameter). Second, the handle also includes amanually actuateable steering means, for example, a joystick or trackball, for directing the movement of the flexible shaft (by means ofsteering wires implanted in the flexible shaft described more fullyhereinbelow). Finally, the handle may include an additional electricalpower supply and an on/off switch for selectively supplying electricalpower to the attachments.

More particularly, with respect to the flexible shaft, the shaftcomprises a tubular sheath, preferably formed of a simple elastomericmaterial which is tissue-compatible and which is sterilizable (i.e., issufficiently rugged to withstand an autoclave). Various lengths of thisflexible shaft may be provided in conjunction with the presentinvention. In this case, the flexible shaft and the handle should beseparable. If separable, the interface between the proximal end of theflexible shaft and the distal end of the handle should include acoupling means for the drive components.

Specifically regarding the drive components of the flexible shaft,within the elastomeric tubular sheath is a smaller fixed tube whichcontains a flexible drive shaft which is capable of rotating within thefixed tube. The flexible drive shaft, itself, simply must be capable oftranslating a torque from the motor in the handle to the distal end ofthe flexible drive shaft, while still being flexible enough to be bent,angled, curved, etc. as the surgeon deems necessary to “snake” throughthe vessel of the patient up to the occluded section. For example, theflexible drive shaft may comprise a woven steel fiber cable. It shall berecognized that other flexible drive shafts may be suitable for thispurpose.

In order to securely engage an attachment, such as the vessel and lumenexpander attachment which is the subject of the present invention (asdescribed more fully hereinbelow), it is preferred that the distal endof the flexible shaft include a stability gripping feature, whichpreferably is simply a set of prongs which engage a pair of recesses inthe coupling end of the attachment (as described more fullyhereinbelow). Further, the distal end of the flexible drive shaft musthave a conformation which permits the continued translation of torque.For example, the distal end of the flexible drive shaft may behexagonal, thereby fitting into a hexagonal recess in the couplinginterface of the attachment. The distal end of the flexible drive shaftmay further include additional topological features which enhance theengagement of the flexible drive shaft to a potential attachment, butwhich are stationary and thereby provide a stable reference position forapplying the rotation to only a portion of the attachment (so that theentire attachment does not rotate when the torque is applied to oneportion of the attachment).

As suggested above, in conjunction with the manually actuateablesteering means mounted to the handle, the flexible shaft furtherincludes at least two steering wires which are flexible, but which arecoupled to the inner surface of the flexible shaft near the distal endthereof. The steering wires may be axially translated relative to oneanother by actuation of the manually actuateable steering means, whichaction causes the flexible shaft to bend and curve accordingly.

Also as suggested above, in conjunction with the remote status indicatorof the handle, the flexible shaft further contains an electrical leadfor coupling to the attachments. This electrical lead channels a signalfrom the attachment to the handle for indicating the status of theattachment (for example, the diametric extent to which the attachmentdevice has expanded to open the vessel or lumen).

More particularly, with respect to the vessel and lumen expanderattachment of the present invention, the attachment has severaldifferent potential embodiments, and preferred ones are disclosed hereinas examples. The attachment is fitted with at least one linear driveextension, which is most simply described as a turning rod. In bothembodiments, this turning rod comprises an elongate cylindrical rodhaving first and second elongate ends. A discontinuous threading isprovided on the outer surface of the rod, and extends from a positionwhich is a short distance from the first end to a position which is ashort distance from the second end. The threading is discontinuousinsofar as the threading on the upper half of the rod is directed in onedirection, and the threading on the lower half is oriented in theopposing direction. A pair of nuts are mounted on the rod, a first nutbeing mounted on the threading of the upper half, and a second nut beingmounted on the threading of the lower half. Rotation of the rod aboutits elongate axis, therefore, while preventing the nuts from rotatingtherewith, causes the nuts to either travel towards one another or apartfrom one another, in accordance with the direction of relative rotationand threading.

At each of the unthreaded elongate ends of the rod is also provided acircumferential recess, in which a washer is mounted. The washers arecoupled to one another by elongate pins which extend in parallel withthe rod. The washers are mounted to the rod such that the rod may rotatewhile the washers remain relatively motionless. In fact, the lowerwasher includes a topological feature which couples to the correspondingstability gripping feature of the flexible shaft of theelectromechanical driver device such that the washers do not moverelative to the driver mechanism, but such that free rotation of the rod200 relative to them is not inhibited.

The nuts which are mounted to the rod include at least one tracking holewhich mates with the pins which couple the washers together, such thatthey may travel linearly along the extent of the rod, but areconstrained against rotation with the rod.

At the first end of the rod, the radial face of the cylinder includes ajoining means (for example, a hexagonal coupling recess) for coupling tothe flexible drive shaft of the electromechanical driver device. Thatis, when the attachment is mated to the electromechanical driver device,the rod is in mechanical communication with the flexible drive shaftsuch that the activation of the motor of the electromechanical driverdevice activates the rod, causing the nuts to travel along the rod,either toward one another, or away from one another in accordance withthe specific orientations of the threading.

In a preferred embodiment, each of the two nuts are coupled to oneanother at a plurality of circumferential sites by means of a series offlexible joints. More particularly, each of the joints is formed by apair of spokes, one of which is attached to the first nut at acircumferential site thereon, and the other being similarly mounted onthe second nut. Each spoke is fixed at one end to its respective nut bya joint which permits the spoke to rotate radially outwardly. At theother end of each spoke, each is coupled by a similar joint to thedistal end of a corresponding opposing spoke, such that the connectedspokes may expand radially outwardly in an umbrella-like fashion, whenthe nuts are brought together, and swing radially inwardly when the nutstravel apart. It shall be understood that the spokes need not bedirectly coupled with one another, but instead may be coupled togetherby a third pin which is jointed with the distal ends of the spokes, andmoves radially with respect to the rod in accordance with the motion ofthe nuts, but which remains parallel to the rod.

The distal ends of the spokes are also coupled with a flexible tubularmaterial which forms a continuous expanding surface as the nuts arebrought together. More particularly, the flexible tube, or shroud,includes sufficient axial rigidity (for example, by means of axialribs), but sufficient radial expandability such that the expandingspokes create a cylindrical structure having a constant diameter and aseries of radially spaced apart spokes extending from the inner surfaceof the flexible shroud to the central axis of the rod. In the version ofthis embodiment in which the spokes are separately jointed with theinterior surface of the cylindrical structure, there are at least twoaxially separate groups of radially spaced apart spokes extending fromthe inner surface of the flexible shroud to the central axis of the rod.Inasmuch as the flexible shroud does not include a radially facingsurface at either axial end thereof, only the rod and the spokes inhibitthe free passage of fluid through the vessel as the expansion is beingprovided.

It shall be further understood that the invention may be constructed andcoupled to the flexible drive shaft in such a way that once theattachment has been expanded to the proper amount (in an analog manner),it may be decoupled and remain as a permanent stent in the vessel orlumen. Future collapse and removal of the stent may be possible, or atleast affected in a less destructive manner than other stents of theprior art, especially stents which are not collapsible.

In practice, this attachment may be utilized in the following manner.The surgeon user begins by coupling the attachment to the distal end ofthe flexible shaft of the electromechanical driver and making certainthat the nuts have been extended to their farthest possible separationsuch that the flexible shroud is in its most radially compact form. Theflexible shaft and attachment are then introduced into the vessel orlumen at the desired point of entry, for example into the femoral arteryin the case of a blockage of a cardiovascular vessel in the vicinity ofthe heart. The flexible shaft and attachment are then advanced up to andthrough the partially occluded section of the vessel or lumen. Theguidance of the flexible shaft up through the vessel or lumen isprovided by remote steering wire actuation in the handle of theelectromechanical driver device (as described more fully hereinabove,and in U.S. patent application Ser. No. 09/324,452, identified above).As mentioned above, this attachment, and in fact, this entire procedureis best applicable in circumstances in which the patient does not havecomplete blockage of the vessel, inasmuch as it is necessary to advancethe attachment into the occluded section.

Once the attachment is properly positioned, the surgeon begins byactuating the finger trigger in the handle of the electromechanicaldriver device, causing the flexible drive shaft within the flexibleshaft to rotate. The coupling of the attachment with the distal end ofthe flexible drive shaft causes the discontinuously threaded elongaterod to rotate (and only the discontinuously threaded elongate rod). Thenuts then advance towards one another, causing the spokes to rotateoutward and to radially open the flexible tube thereby pressing againstthe occluded vessel walls and radially opening the vessel to permitgreater fluid flow. In conjunction with the versions of this embodimentin which the attachment may be remotely decoupled from the distal end ofthe flexible shaft of the electromechanical driver device, it may befound appropriate by the surgeon to leave the expanded stent-likestructure in place to at least slow the potential re-stenosis of thevessel.

A BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a handle and flexible shaft of the presentinvention, herein internal features of the elements are provided inphantom;

FIG. 2 is a side view of the discontinuously threaded elongate rod, nutsand washer subassembly, which is an aspect of the present invention;

FIGS. 3a and 3 b are side cross-section views of one version of presentinvention in which the complete attachment assembly is in closed andexpanded dispositions, respectively; and

FIGS. 4a and 4 b are side cross-section views of another version of thepresent invention in which the attachment assembly is in semi-expandedand fully expanded dispositions.

A DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

While the present invention will be described more fully hereinafterwith reference to the accompanying drawings, in which particularembodiments are shown, and with respect to methods of use, it is to beunderstood at the outset that persons skilled in the art may modify theinvention herein described while achieving the functions and results ofthis invention. Accordingly, the descriptions which follow are to beunderstood as illustrative and exemplary of specific structures, aspectsand features within the broad scope of the present invention and not aslimiting of such broad scope. Like numbers refer to similar features oflike elements throughout.

More particularly, the present invention comprises a vessel and lumenexpander attachment for use with an electromechanical driver device. Inorder to fully understand the use and function of the attachment it isuseful to discuss the electromechanical driver device. Therefore,referring now to FIG. 1, the electromechanical driver device isdescribed hereinbelow. The electromechanical driver device has a handleportion 102 and a flexible drive shaft portion 104. The handle 102includes a portion which is shaped in a manner which is easily grippedby the surgeon operator. For example, in the embodiment provided herein,the handle 102 comprises a pistol grip-styled portion. The grip portion106 includes at least one, and in the present embodiment exactly one,finger actuateable trigger 108. The finger trigger 108 is coupled to amotor 112 housed within the interior volume of the handle 102, whichturns a flexible drive shaft (described more fully, hereinbelow).

More particularly, with respect to the motor 112, it is a dual directionmotor coupled to a manual drive switch 116 and powered by a power source114. The manual drive switch 116 is provided on the top of the handle100, such that the surgeon user can selectively alter the turningdirection of the motor 112, and thereby, the flexible shaft 122. Itshall be understood that alternative power sources, including dualdirect current sources or single remote alternating current sources(such as the alternating current provided from standard United States120 Volt, 60 Hertz wall outlets) may be used in conjunction withalternative embodiments. In the event that the electromechanical driverdevice should be useable with an alternating current, either atransformer can be included between the motor 112 and the power source114, or a more sophisticated intermediate gearing assembly may beprovided between the motor 112 and the flexible drive shaft 136.

In addition to the motor 110 and related power and drive switchelements, the handle 100 further include a remote status indicator 118which may comprise an LCD (or similar read out device) by which the usermay gain knowledge of the position of components (for example whetherthe spokes are at the closed position or at a definite expandeddiameter). The handle 100 further includes a manually actuateablesteering means 124 for causing the remote movement of the distal end 121of the flexible shaft 122, which in the present embodiment comprises atrackball 124, coupled to a plurality of steering wires 126. Thesteering wires 126 extend along the flexible shaft 122 (described morefully hereinbelow) and are coupled to the distal end 121 of the flexibleshaft 122. When the trackball 124 is rotated, the steering wires 126 arepulled, and the distal end 121 of the flexible shaft 122 turnscorrespondingly.

More particularly, with respect to the flexible shaft 122, the shaftcomprises a tubular sheath 128 which is formed of a tissue-compatible,elastomeric material. As this device is to be reused, it is importantthat the material be sterilizable (i.e., is sufficiently rugged towithstand an autoclave). While the embodiment illustrated comprises acontiguous handle 102 and flexible shaft 122, it shall be understoodthat one having ordinary skill in the art may provide an alternativeembodiment having a separable handle 102 and flexible shaft 122, thuspermitting alternative shaft lengths for alternative purposes. In suchcases, the flexible shaft 122 and the handle 100 should include aninterface between the proximal end of the flexible shaft 122 and thedistal end of the handle 100 which should include a coupling means forthe drive components.

Specifically regarding the drive components 130 of the flexible shaft122, within the elastomeric tubular sheath 128 is a smaller fixed tube134 which contains a flexible drive shaft 136 which is capable ofrotating within the fixed tube 134. The flexible drive shaft 136,itself, simply must be capable of translating a torque from the motor112 in the handle 102 to the distal end 138 of the flexible drive shaft136, while still being flexible enough to be bent, angled, curved, etc.as the surgeon deems necessary to “snake” the attachment through thevessel of the patient. For example, the flexible drive shaft 136 maycomprise a woven steel fiber cable, a high tensile strength polymericmaterial, or a sufficiently flexible unitary metal shaft.

In order to securely engage the attachment to be used with thiselectromechanical driver device, it is preferred that the distal end 121of the flexible shaft 122 include a stability gripping feature 139,which preferably is simply a set of prongs which engage a pair ofrecesses in the coupling end of the attachment (see FIGS. 2-4).

In order for the distal end 138 of the flexible drive shaft 136 tocouple with the attachment, the distal end 138 of the flexible driveshaft 136 must have a conformation which permits the continuedtranslation of torque. In the present embodiment, this coupling isachieved by a geometric fitting, and more precisely, the distal end 138of the flexible drive shaft 136 is hexagonal, and thereby fits into ahexagonal recess in the coupling interface of the attachment (see FIG.2). The remainder of the distal end 138 which is not the flexible driveshaft 136, and which does not move, includes a stable junction feature139 which may also couple with the selected attachment in such a manneras to prevent portions of the attachment which are not to turn inaccordance with the rotation of the flexible drive shaft 136 fromturning.

In conjunction with the manually actuateable steering means 124 mountedto the handle 102, the flexible shaft 122 further includes at least twosteering wires 126 which are flexible, but which are coupled to theinner surface of the flexible shaft 122 near the distal end thereof. Thesteering wires 126 may be axially translated relative to one another byactuation of the manually actuateable steering means 124, which actioncauses the flexible shaft 122 to bend and curve accordingly.

In conjunction with the remote status indicator 118 of the handle 102,the flexible shaft 122 further contains an electrical lead 120 forcoupling to the attachments. This electrical lead 120 channels a signalfrom the attachment to the handle 102 for indicating the status of theattachment (for example, the diametric extent to which the attachmenthas expanded to open the vessel or lumen).

Referring now to FIG. 2, the vessel and lumen expander attachment isfitted with a linear drive extension, or turning rod 200. In bothembodiments to be described herein, this turning rod 200 comprises anelongate cylindrical rod 200 having first and second elongate ends202,204, respectively. A discontinuous threading 206,208 is provided onthe outer surface of the rod 200, and extends from a position which is ashort distance from the first elongate end 202 to a position which is ashort distance from the second elongate end 204. The threading isdiscontinuous insofar as the threading 206 on the upper half of the rodis directed in one direction, and the threading 208 on the lower half isoriented in the opposite direction. A pair of nuts 210, 212 are mountedon the rod 200, the first nut 210 being mounted on the threading 206 ofthe upper half, and a second nut 212 being mounted on the threading 208of the lower half. Rotation of the rod 200 about its elongate axis,therefore, while preventing the nuts 210,212 from rotating therewith,causes the nuts 210,212 to either travel towards one another or apartfrom one another, in accordance with the direction of relative rotationand threading.

At each of the unthreaded elongate ends 202,204 of the rod 200 is alsoprovided a circumferential recess 214, 216, respectively, in which awasher 218,220 is mounted. The washers 218,220 are coupled to oneanother by elongate pins 222 a,222 b which extend in parallel with theelongate cylindrical rod 200. The washers 218,220 are mounted to the rod200 such that the rod 200 may rotate while the washers 218,200 remainrelatively motionless. In fact, the lower washer 220 includes a pair ofrecesses 223 which couple to the corresponding stability grippingfeature (best shown as item 139 on FIG. 1) of the flexible shaft of theelectromechanical driver device such that the washers 218,220 do notmove relative to the driver mechanism, but such that free rotation ofthe rod 200 relative to them is not inhibited.

The nuts 210,212 which are mounted to the rod 200 include a pair oftracking holes 224 through which the elongate pins 222 a,222 b couplethe washers 218,200 together, such that the nuts 210,212 may travellinearly along the extent of the rod 200, but are constrained againstrotation with the rod 200.

At the first end 202 of the rod 200, the radial face of the cylinderincludes a coupling recess 225 (for example, a hexagonal socket) forcoupling to the flexible drive shaft of the electromechanical driverdevice. That is, when the attachment is mated to the electromechanicaldriver device, the rod 200 is in mechanical communication with at leastone flexible drive shaft such that the activation of the motors of theelectromechanical driver device activates the rod, causing the nuts210,212 to travel along the rod 200, either toward one another, or awayfrom one another in accordance with the specific orientations of thethreading.

Referring now to FIGS. 3a and 3 b, a first embodiment of the presentinvention is provided in a pair of cross-sectional views; the firstillustrating the attachment in a semi-expanded position, and the secondillustrating the attachment in a fully extended position. In thisembodiment, each of the nuts 210,212 are coupled to one another at aplurality of circumferential sites by means of a series of flexiblejoints, or pivots 230. More particularly, each of the pivots 230 isformed by a pair of spokes 232 a,232 b, one 232 a of which is attachedto the first nut 210 at a circumferential site thereon, and the other232 b being similarly mounted on the second nut 212. Each spoke 232a,232 b is fixed at one end to its respective nut 210,212 by a jointwhich permits the spoke to rotate radially outwardly. At the other endof each spoke 232 a,232 b, each is coupled by a similar joint 234 to thedistal end of the corresponding opposing spoke, such that the connectedspokes may expand radially outwardly in an umbrella-like fashion, whenthe nuts 210,212 are brought together, and swing radially inwardly whenthe nuts 210,212 travel apart.

Referring now to FIGS. 4a and 4 b, a second embodiment is shown. Itshall be understood that the spokes 232 a,232 b need not be directlycoupled with one another, but instead may be coupled together by a thirdpin 236 which is jointed with the distal ends of the spokes 232 a,232 b,and which moves radially with respect to the rod 200 in accordance withthe motion of the nuts 210,212, but which remains parallel to the rod200.

In both embodiments, the distal ends of the spokes 232 a,232 b are alsocoupled with a flexible tubular material 240 which forms a continuousexpanding surface as the nuts 210,212 are brought together. Moreparticularly, the flexible tube 240 includes sufficient axial rigidity(for example, by means of axial ribs, not shown), but sufficient radialexpandability such that the expanding spokes 232 a,232 b create acylindrical structure having a constant diameter and a series ofradially spaced apart spokes extending from the inner surface of theflexible tube 240 to the central axis of the rod 200. In the version ofthis embodiment in which the spokes 232 a,232 b are separately jointedwith the interior surface of the cylindrical structure, there are atleast two axially separate groups of radially spaced apart spokesextending from the inner surface of the flexible tube 240 to the centralaxis of the rod 200. Inasmuch as the flexible tube 240 does not includea radially facing surface (a closed top or bottom of the cylinder) ateither axial end thereof, only the central rod 200 and the spokesinhibit the free passage of fluid through the vessel as the expansion isbeing provided.

It shall be further understood that the invention may be constructed andcoupled to the flexible shaft of the electromechanical driver in such away that once the attachment has been expanded to the proper amount (inan analog manner), it may be decoupled and remain as a permanent stentin the vessel. Future collapse and removal of the stent may be possible,or at least affected in a less destructive manner than other stents ofthe prior art, especially stents which are not collapsible.

In practice, this attachment may be utilized in the following manner.The surgeon user begins by coupling the attachment to the distal end ofthe flexible shaft of the electromechanical driver device, makingcertain that the nuts 210,212 have been extended to their farthestpossible separation such that the flexible tube 240 is in its mostradially compact form. The flexible shaft and the attachment are thenintroduced into the vessel or lumen at the desired point of entry, forexample, into the femoral artery in the case of a blockage of acardiovascular vessel in the vicinity of the heart. The flexible shaftand the attachment are then advanced up to and through the partiallyoccluded section of the vessel. The guidance of the flexible shaft upthrough the vessel is provided by remote steering wire actuation in thehandle of the electromechanical driver device (as described more fullyhereinabove, and in U.S. patent application Ser. No. 09/324,452,identified above). As mentioned above, this attachment, and in fact,this entire procedure is best applicable in circumstances in which thepatient does not have complete blockage of the vessel, inasmuch as it isnecessary to advance the attachment into the occluded section.

Once the attachment is properly positioned, the surgeon begins byactuating the finger trigger in the handle of the electromechanicaldriver device, causing the flexible drive shaft within the flexibleshaft of the electromechanical driver device to rotate. The coupling ofthe attachment with the distal end of the flexible shaft causes thediscontinuously threaded elongate rod 200 (and only the discontinuouslythreaded elongate rod) to rotate. The nuts 210,212 then advance towardsone another, causing the spokes 232 a,232 b to rotate outward and toradially open the flexible tube 240, thereby pressing against theoccluded vessel or lumen walls and radially opening the vessel or lumento permit greater fluid flow.

In conjunction with the versions of this embodiment in which theattachment may be remotely decoupled from the distal end of the flexibleshaft of the electromechanical driver device, it may be foundappropriate by the surgeon to leave the expanded stent-like structure inplace to at least slow the potential re-stenosis of the vessel or lumen.

While there has been described and illustrated new and novel attachmentsfor use with electromagnetic driver surgical instruments for radiallyexpanding occluded vessels and lumens, it will be apparent to thoseskilled in the art that variations and modifications are possiblewithout deviating from the broad spirit and principle of the presentinvention which shall be limited solely by the scope of the claimsappended hereto.

What is claimed is:
 1. A vessel and lumen expanding attachment for usewith an electromechanical driver having an elongated flexible driveshaft including a torque transferring tip, said attachment comprising: arotatable rod having first and second axial portions, which rod ismateable with said torque transferring tip of said electromechanicaldriver, said rod including a first threading disposed on the firstportion, and a second threading disposed on the second portion, whereinthe first and second threadings are oriented in opposition with oneanother; first and second nuts which are mounted about the threadings ofthe first and second portions of said rod, respectively; means forconstraining said first and second nuts from rotating relative to saidrod, such that rotation of said rod causes said first and second nuts totravel toward each other when said rod is rotating in one direction, andaway from one another when said rod is rotating in the oppositedirection; a plurality of jointed radially expanding and retractingspokes coupled to said first and second nuts, said jointed radiallyexpanding and retracting spokes being expandable and retractable inaccordance with the relative axial motion of said first and second nuts;and a radially flexible tubular shroud mounted about said rod, saidfirst and second nuts, and said spokes, which is coupled on the interiorsurface thereof to said spokes, such that said shroud may be expandedand alternatively retracted radially in accordance with the rotation ofsaid rod.
 2. The vessel and lumen expanding attachment as set forth inclaim 1, wherein the means for constraining said first and second nutsfrom rotating relative to said rod comprises a pair of washers looselymounted at opposing axial ends of the rod, mounted such that therotation of said rod does not cause the rotation of the washers, whereinsaid washers are coupled to one another by at least one pin whichextends in parallel with said rod, and which extends through said firstand second nuts, thereby forming a track along which said first andsecond nuts may travel axially, but which constrains said first andsecond nuts against rotational motion.
 3. The vessel and lumen expandingattachment as set forth in claim 1, wherein said radially flexibletubular shroud mounted about said rod, said first and second nuts, andsaid spokes further includes axially rigid ribs which support saidshroud in a axially constant diameter disposition.
 4. The vessel andlumen expanding attachment as set forth in claim 1, wherein each of saidjointed radially expanding and retracting spokes coupled to said firstand second nuts, comprises; a pair of elongate members having distal andproximal ends, said proximal ends of each being pivotably coupled at aposition on an outer lateral surface of one of said first and secondnuts, respectively, to permit said the corresponding elongate member topivot wherein the corresponding elongate member may swing through arange of positions including parallel to said rod and radially outwardto a position which is perpendicular to said rod; and a pivot jointformed by the coupling of said distal ends of said elongate members,such that said pair of elongate members swing together from orientationswhich are parallel to said rod and orientations which are perpendicularto said rod as said first and second nuts move toward one another inaccordance with the actuation of said electromechanical driver, wherebysaid pivot joint formed by said distal ends of the elongate membersmoves radially outward from said rod.
 5. The vessel and lumen expandingattachment as set forth in claim 4, wherein the lengths of said elongatemembers are determined such that said pivot joint formed by said distalends of the elongate members does not move axially relative to said rod.6. The vessel and lumen expanding attachment as set forth in claim 4,wherein said pivot joint formed by said distal ends of the elongatemembers is coupled to said radially flexible tubular shroud at an innersurface thereof.
 7. The vessel and lumen expanding attachment as setforth in claim 1, wherein each of the jointed radially expanding andretracting spokes coupled to said first and second nuts, comprises;first and second elongate members each having distal and proximal ends,said proximal ends of each being pivotably coupled at a position on anouter lateral surface of one of said first and second nuts,respectively, to permit the corresponding elongate member to pivotwherein the corresponding elongate member may swing through a range ofpositions including parallel to said rod and radially outward to aposition which is perpendicular to said rod; a third elongate memberwhich is oriented in parallel with said rod; a pair of pivot jointsformed by coupling of said distal ends of each of said first and secondelongate members to opposing ends of said third elongate member, suchthat as each of said first and second elongate members swing fromorientations which are parallel to said rod and orientations which areperpendicular to said rod as said first and second nuts move toward oneanother in accordance with the actuation of said electromechanicaldriver, said pivot joints formed by said distal ends of said first andsecond elongate members with said third elongate member causes saidthird elongate member to move radially outward from said rod.
 8. Thevessel and lumen expanding attachment as set forth in claim 7, whereinthe lengths of said first, second, and third elongate members aredetermined such that said third elongate member does not move axiallyrelative to said rod.
 9. The vessel and lumen expanding attachment asset forth in claim 7, wherein said third elongate member is coupled tosaid radially flexible tubular shroud at an inner surface thereof.